The US inquiry into alleged Russian meddling during the 2016 election could be under threat after President Donald Trump fired Attorney General Jeff Sessions, top opposition Democrats say.

Nancy Pelosi, who leads Democrats in the House of Representatives, called the decision a “blatant attempt” to end or impede the investigation.

The probe has been criticised by Mr Sessions’s successor Matthew Whitaker.

The Democrats, who won the House in the mid-terms, have vowed to protect it.

Some Republicans appear to have shared the Democrats’ concern over the future of the inquiry, which is being led by Special Counsel Robert Mueller. Senator Susan Collins and Mitt Romney said it should not be impeded in any way.

Mr Mueller is investigating alleged collusion between the Trump campaign and Russia, resulting in a series of criminal charges against several Trump associates.

Mr Trump has vehemently denied any collusion took place, and repeatedly called for the inquiry to be shut down, calling it “the greatest political witch hunt in history”.

Democrats see this latest move as an attempt to do just that.

“It is impossible to read Attorney General Sessions’ firing as anything other than another blatant attempt by @realDonaldTrump to undermine and end Special Counsel Mueller’s investigation,” Ms Pelosi – a front-runner to become speaker of the House of Representatives following this week’s mid-terms – tweeted.

She went on to argue that, “given his record of threats to undermine and weaken the Russia investigation”, Mr Whitaker should follow in Mr Sessions’ footsteps and recuse himself.

Her words were echoed by Democratic party Senate leader Chuck Schumer, who added: “Clearly, the president has something to hide.”

The sacking followed months of Mr Trump criticising Mr Sessions, mainly for his decision to step aside from the Russia inquiry in March 2017.

Mr Sessions removed himself from the probe after Democrats accused him of failing to disclose contacts he had had with the Russian ambassador as a senior adviser to Mr Trump’s campaign.

In July 2017 Mr Trump told the New York Times: “Sessions should have never recused himself, and if he was going to recuse himself, he should have told me before he took the job and I would have picked somebody else.”

In a resignation letter, Mr Sessions – a former Alabama senator who was an early supporter of Mr Trump – made clear the decision to go was not his own. -BBC